Fabricate Three-dimensional Scaffolds For Tissue Engineering Based On Macroscopic Supramolecular Assembly

In recent years, people are constantly exploring and practicing the dream of saving organs and even the whole body. It is desirable to build a three-dimensional scaffold with chemical specificity for cell culture in vitro, thus to generate new organs to solve the problem of organ deficiency and organ aging. Three-dimensional scaffolds are the core element of tissue engineering and essential three-dimensional media for the growths of cells, which adsorb and penetrate on the scaffolds. The traditional methods of preparing the three-dimensional scaffolds don't satisfy the requirements of precise, high connectivity and high mechanical properties and so on, since it is difficult to build a scaffold with different chemical composition and biological properties in three-dimensional space. There are a few methods to solve it, such as 3D printing technology, two-photon lithography technology. However, they all have some drawbacks. Our group proposed a new method which was macroscopic supramolecular assembly combined efficient magnetic field for localization to obtain the the precise and stable three-dimensional scaffolds for tissue engineering. This method not only solved the problem of resolution in 3D printing technology, but also avoided the unfavorable factors of time-consuming and high cost in two-photon lithography.This paper prepared three biomolecules contained host and guest groups on magnetic-response strip-like polydimethylsilicon(PDMS)building blocks of carboxylated chitosan grafted with cyclodextrin(CCS-CD), cyclodextrin-modified hyaluronic acid(HA-CD)and cholesterol-modified poly(L-lysine)(PLL-Chol.), and then built the three-dimensional scaffolds via the host-guest interactions, then the three-dimensional scaffolds applied for cell culture. The effects of the system on the cell growth were studied. The cell culture experiments were carried out from the drug itself, the two-dimensional multilayers and the three-dimensional scaffolds. The main results were as follows:1. We fabricated polyelectrolyte multilayers on building blocks by Layer-by-Layer technology, included the poly(L-lysine)(PLL) and CCS-CD, PLL-Chol. and hyaluronic acid, PLL and HA-CD.2. We introduced three host and guest molecules on the surface of the PDMS building blocks to carry out directly assembly experiment and quantitative adhesion test experiment, respectively.3. We obtained the three-dimensional ordered structures through macroscopic supramolecular as'sembly combined efficient magnetic field for localization, then realized the transition from two-dimensional plane to three-dimensional space. The results of cell culture told us that cells were adsorbed and grown at a certain density on the surface of two three-dimensional scaffolds, one was prepared through the host-guest recognition interactions of CCS-CD and PLL-Chol., another was prepared through the host-guest recognition interactions of HA-CD and PLL-Chol.In summary, this thesis demonstrates that the natural biological substances are more biocompatible than the synthetic materials and are more suitable for cell culture.